Pneumatic sheet metal hammer



Aug. 5, 1952 G. c. CURRENT PNEUMATIC SHEET METAL HAMMER 2 SHEETS-SHEET 1 Filed Feb. 13, 1951 I N V EN TOR.

050/766 C Cufimswr mmozuflwvzdwn Arron/vars Aug. 5, 1952 G. C. CURRENT PNEUMATIC SHEET METAL HAMMER 2 SHEETS-SHEET 2 Filed Feb. 15; 1951 INVENTOR. -6"0m9 C C0525;-

Patented Aug. 5, 1952 UNITED sTA TEs EN 'F PNEUMATIC SHEET METAL AM ER George C. Current, Dumas, Tex. U

Application February 13,1951, Serial No. 210,642 a Claims. (01. 15342) is balanced for more convenient use with less fatigue on the part of the operator; whichineludes an operating and control unit and tap carrying arms of difierent shapes releasably connected to the operating and control unit so that the arms can-be interchanged for different opergating conditions; which can be usedin restricted spaces, such as in. automobile doors, through small openings in the door frames, without removing the upholstery panels, and in automobile body tops by loosening the head lining at its edge, but without removing the lining; which includes a piston or hammer head and a tap or plunger and means for operating the tap in a direction difierent from the direction of operation of the piston; and which is simple and durable in construction, economical to manufacture', easy to use and positive and effective in operation.

: Other objects and advantages will become apparent from a consideration of the following description and appended claims in conjunction with the accompanying drawings, wherein:

Figure 1 is a side elevational view of a pneumatic sheet metal hammer illustrative of the invention;

Figure 2 is an elevational view of the hammer looking at the upper side of the hammer as illustrated in Figure 1;

Figure 3 is a fragmentary cross-sectional View on an enlarged scale on the line 3-3 of Figure 2; showing the left-hand portion of the hammer illustrated in Figures 1 and 2; I

Figure 4 is a fragmentary elevational view onan enlarged scale showing the right-handend portion of the hammer as viewed in Figures 1 and 2, a portion being broken away and shown in cross-section to better illustrate the construction thereof; 4

Figures 5, 6, 7, 8, 9, 10, 11 and 12 are transverse cross-sectional views on the corresponding section lines on Figure 3;

Figure 13 is an end elevational view of the hammer looking at the left-hand end as viewed in Figure 3; V

Figure 14'is a side elevational View showing a modified form of pressure arm connected to'the hammer; and

Figure 15 is a cross-sectional view showing a inder intermediate the length of the. cylinder.

, The transverse partition, l3 comprises a circular disc l4 having spaced apart apertures, as

indicated at I5 in Figure 8, extending therethrough, and spaced around the'center-of the disc substantially at one side of a diameter thereof, and a disc-shaped nut IS disposed at the side of the disc I l-adjacent the end plug I I and spaced from the disc by an annular washer I'I having its periphery in contact with the innersurface of the cylinder. lfhe other side of thedisc I4 bears against an annular shoulder I8 in, the cylinder; so that the transverse partition is definitely located in the cylinder, and the washer I1 is compressed between the nut I6 andthe disc I4. The nut I6 is provided with a central bore I 9 constituting a fluid pasage through the nut and surrounded by an annular flange or boss 20 constituting a valve seat. The fluid passage I9 communicates with the passages I5 in the disc l4 through the space 2| provided between the disc I4 and the nut I6 by the annular washer I1.

,The end plug II is provided with a bore 22 extending coaxially therethrough and through a sleeve or boss formation 23 at the inner side and the valve-seat when the valve is closed.

'Ascrew plug-:28 is threaded into the outer end of the bore 22 and a compression spring 29 is disposed inthe .bore, between this plug and, the adjacent end of the plunger to resiliently urgethe plunger into'valve closing engagement with the valve seat.

A second bore 30 extends through the end plug II at a location spaced from-the bore 22 and is providedin its outerend with a screw- 7 threaded counterbore 3I into whicha fitting 32 is threaded to connect a fluid line or conduit 33 tothe hammer,

An, elbow tube 34 isj disposedjin anopening r in the disc I4 and extends from the peripheral surface of the disc to a location at the end of the disc adjacent the nut I6 and concentric to the bore I9 in the nut. An aperture 35 in the Wall of the cylinder I8 registers with the end of the tube 34 at the peripheral surface of the disc.

A cylindrical detent 35 is secured to the. head end of the valve plunger and extends into the adjacent end of the tube 34, and an elongated plunger element 3'! is slidably received in the aperture 35 in the cylinder andextends fromthe outside of the cylinder into the adjacentend of.

the tube 34. Ball elements 38 are disposed in the tube between the plunger. element 31:and :the. detent 36 and are effective to move thehead. of

the valve away from the valve seat ZIlwhen the 7 element 31 is forced inwardly of the cylinder.

' A lever fl is-pivotallyconnected at "one end to the cylinder by a pivotal connection 491*?10ciated *at tlie side -of-' the-transverse partition remote fi om the'end plug {I I and bearsintermediateits length on the outer-end" of-l-the-elementdli A jliand lever'jor; valvetrigger-= 41 is pivotally'. connectedto the cylinderat one :end by, connec- "tion 4'2"loc atedadjacentythe'end-plug H and -bears intermediate its length on the end "of the lvr V 3-9'--remote from-"themivotal connection 40,

sothahmanual pressurefiforcing; the lever 4 I to- 'wa-rd the cyli-nder' willopenthe valve. A compression spring 343is' disposed between the lever F41" andthe'cy-linder" and resiliently urges the lever away from" the cylinder: 7

With this arrangement, air from the conduit 33 as continuousl'yadinitted into the space within the cylinder*and between the-nut I6 and the '--e nd plug II and surrounding-the-valve plunger 24'5- a'nd, when the have!" 4 I ismanually 7 pressed toward-the cylinder; thiscompressed air is admitted through the. bore- I9- in the nut and "the apertures 'l 5 in the-disc M -tothe-space Within the cylinder at the sides-ofthe=intermediate partition' remote from the end plu-g I I.

Apiston:45 is slidably mounted in the cylinw :de'r 'betwe'en the transverse "partition [3 i and the endplug zlsz and'the end-plug lziis-provided-with a: coaxial boreahaving atiits'inner end a counterhorec lfij; A. compressionspring 41 is received at,

onez endf: in the counterbore 45" bearing against the annular shoulder at the inner -end' of this ..connterbore;andt. bearsiat its other end against thee-adj acentr'end f =the :piston l 5": to: resiliently u'rgerthe piston toward the= transverse partition 3 13s, The'zend of the: spring--41 in engagement with the: piston'sis zmaintained'f inlcenter position relame; to the piston: by i an anvil extension 48 1 projectings. outwardly-:" from the: corresponding end oft-he: piston anda'received in the spring.

'Acfb'leedi opening-49 extends through the wall OfIZ'bh'ef; cylinder :I Iii-and communicates with the "5132683121.;503 thatzwh'en the" head-of the valve plunger is in'va'lve closing engagement with the valvesseati 20 air 'will bleed outiof" the space be-- .itweemtheizpistorr and thetransverse partitiQn JIGj permitting the piston to move toward and into? contactwith' theetransverse partition, as i'llustratedfin' Figurerb; underf-the influence of the sprin 41.

' Anelongated;tubular-arm 50 has one end telescopicallyl received i in" the bore of the end plug I'2iand; is .providedtagainst" this end with anexternal annular groove SI. videdvwith a chordwise' extending bore 52* and The end plug isproa locking pin 53 is slidably mounted inthis bore "and' aengages inthe groove -5I- of the arm 50 to releasably lock-the arm in the end plug I2, as is particularly illustrated in Figure 10. The bore 52 is provided intermediate its length with an annular shoulder, and the pin 53 is provided in termediate its length with a shoulder which engages the shoulder in the bore to limit movement of the pin through thetborein one direction. One endof the bore is closed. by a screw plug 54 and a compression spring 55 disposed in the bore between the screw plug and the adjacent end of the locking pin resiliently urges the locking pin tothe position in which it lockingly engages in.the groove 5I of the arm 50. The other end of the pin projects out of the end -plug:and'inwardlydirected manual pressure on thisoutwardly projecting end of the pin will force the pin'inwardly of the bore 52 against the force a of the spring 55 to a-position at which the pin frame by a pivot pin it.

is" clear of the groove 5l and releases the-arm threaded onto the outwardlyprojeeting end of the pin and secures-the pin againstaccidental release oi the arm.

At its-end remote from the end plug" I2,- the arm is provided with anelbow' bend 51; as particularly illustrated in Figure 9, and this end'of the arm" is externally screw-threadedand receives a fiangednut Eli-provided with a central aperture. 'A tap pin '59'has a cylindricalshank slidably received in th'e aperture of the nut 58 and a'disc-shaped head fifl within'the'tubular armat'the inner side' ofthe endj'wall of the nut. The other end of-the shank ofthepm is rounded or pointed, as indicated at 6I; to act on shee-t me'talworlr piecestoremm/e'smaIl dents therefrom; a r v A- ram;6-2 in the-formof'an elongated cylindrical rodextends through th'e arm 50 from a locationadjacentthe elbow bend 51 to a-location-againstthe anvil 48 oft-lie pistonoryhammer head 45, andaseries of ball-elements 63 arejd-isposed in the arm'between'the' head. 63 of the tap pinand'theadjacent-end-of the ram.

With this arrangement. when the piston45'is forced against the adjacent end ofthe' ram by the admission of compressed air between" the I piston' and the-transverse partition I3, this force is'transmittedthroughthe ram and the .ballelements'53to the piny59; forcing the pin against a sheet metal workpiece with which the pointed or rounded end of'the pin'is in contact: .When the compressed air is cut off and bleeds through thevent'M, the spring 4'! forces the pistonfaway the outer end ofithe tap pin 59. The intermediate portion of the frame isspaced from thearm 50 to receive a workpiece between the frameran dthe arm.

The frame-is made in twopartsiisjand ,5-9, which are longitudinally curved and pivotally connecte'd'together intermediate the length .ofthe In the arrangement illustrated, the pivot pin is located adjacent-the end of the frame member'fifi and intermediate the'length of the frame member SSJtheframe member 69 extending from the pivotpin along the member 63in overlapping relationship to-the latterto provide a handle H, subject to manual pressure for forcing the abutincnt lplate fi'itoward the tap pin 59. r 7

In using the hammer, the sheet metal work piece is placed between the pin 59 and the abutment plate or foot '6! and the hammer is moved relative to the work piece until the tap pin is on a dent to be removed. Pressure is then applied between the frame member 68 and thehandle portion H of the frame member 59 to clamp the workpiece between the pin and the abutment plate or foot and the valvelever 4! is then squeezed toward the cylinder Hi to admit'compressed air to the hammer and provide a hafnmering action by the tap pin. 1 V

In the modified. arrangement illustrated in Figure 14, the parts are all the same as described above, except that a modified arm carrying a modified frame 16 has been substituted for the arm 50 and frame 65 ofthe first-describedform of the invention. K lhe arm 75 is straight and shorter than the 'arm 50 and the ball elements 63 are omitted pin, the other end of the part 18 overlapping the part ll and providing'a handle for manually forcing the plate 79 toward the pin carrying end of the arm 75.

In the modified arrangement shown in Figure [5, the pivotally mounted portion of the frame, indicated at 69, but which may be either the part 69 or the part 1'8 or the corresponding part of any other frame, has a universal connection with the associated foot or abutment plate.

In this arrangement, the framepart is-provided at its plate carrying end with a ball forma tion 8! and the plate 3! is provided with a socket including an outer part 82 receiving the ball formation and secured to the plate by'screws 83 extending through registering apertures in the plate and in an annular external flange 8% on: the

socket $2, and an insert disposed within the outer part 82 and completinga substantially spherical ball receiving space within the socket. The outer part 82' of the socket is provided at its end remote from the plate with 'a beveled opening through which the arm 68 extends.

The invention may be embodied inother speciflc forms without departing from the spirit or essential characteristics thereof. 7 The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the'appended claims rather than by the' foregoing description, and all changes which come within the meaningand range of equivalenceof the claims are, therefore, intended to'be embraced therein.

What is claimed is:

1. A'pneumatic tap hammer comprising a cylinder, means providing a transverse'partition in;

said cylinder intermediate the length thereof, end

plugs secured one in each end of said cylinder, a

piston slidably mounted in said cylinder between said transverse partition andone of said end plugs, a valve plunger in said cylinder between "said transversepartition and the other end plug,

said-one end plug havin ga bore extending therethrough, a tubular arm having one 'endreceived inth'e bore ofsaid one plug and extending outwardly-from said one plug, means releasably connesting said-armto said one plug, a tap pin movablymounted in said arm at the otherend thereo'f, m an-sextending through said tubular arm frohr said tap pin to said piston for transmitting fmoveme'n't ofsaid piston to said tap pin, a' frame "secured at one end to said arm at a'location adjacent said cylinder and having its other end disposed adjacentsaid tap pin'and itsintermediate portionspaced from the in'termediate portion of said amend frame including two members pivotally connected together with their adjacent ends overlapping to" provide a leverage for manually forcing said outer end of said frame toward said tap pin, said transverse partition having a valve seat on the side thereof adjacent said valve plungerv and a fluid passageleading from said valveseat to the other side thereof, said other end plug having a guide means thereonmaintaining'said valve plunger in alignment with said valve seat and a fluid passage therethrough,

spring means acting between said otherend plug and. said valve plunger resiliently urging said plunger into valve closing engagementwith said valve seat, a valve operating lever mounted'on said cylinder, means extending through said transverse partition connecting said lever to said valve" plunger for manually openin said 'valve to admit fluid tosaid transverse partition and to the space betweensaid transverse partition and said piston, said cylinder having a vent'opening connected to said space for ventingpressure fluid therefrom, spring means acting between said piston, andsaid one end plug resiliently urging said piston toward said, transverse partition, and a fittingsecured to said other end plug in registry with the fluid passage therethrough for connecting a pressure fluid conduit to-the hammer.

2. A pneumatic tap hammer comprising a cylinder, means providing a transverse partition in said cylinder intermediate the length thereof, end plugs secured one in each end of said cylinder,'a piston slidably mounted in said cylinder between said transverse partition and one of said end plugs, a valve plunger in said cylinder between said transverse partition and the other end plug, saidone end plug having a bore extending' therethrough, a tubular arm having one end received in the bore of said one plug and extending outwardly from said one plug, means re- .leasably connecting said arm to said one plug,

a tap pin movably mounted in said' arm at the other end thereof, means extending through said tubular arm from said tap pin to said piston for transmitting .movement of said piston to said tap pin, a frame secured at one end to said arm at a location adjacent said cylinder and having its other end disposed adjacent said tap-pin and its intermediate portion spaced from the intermediate portion of said arm, said frame including two members pivotally connectedtogether withgtheir adjacent ends overlapping to provide a:.leverage for manually-forcing said outer end of said'frame toward said tap pin, said transpassage leading from said valve seat to the other side thereof; said other end plug having a guide means thereon maintaining said valve plunger "in alignment ,withgsaid-valve seat'and. aiiuid mounted onsaid cylinder, through said transverse partition connecting said lever 'tosaid valve plunger for manually opening" said valve to admit'fluidto saidtransverse partition andito the space between said transpassage therethrough, spring means. acting between said other end plug and said valverplunger resiliently urging-said; plunger into valve closing engagement with said valve seat, a, valve :opersaid transverse partition .and said piston, said;

cylinder having a-vent openingrconnectedto said space-for venting pressure.fluid.therefrom,.-spring meansacting between said piston and said one end plug resiliently urging said piston toward .said transverse partition, and afittingsecured to said. other end plug in registry with the 'fiuid passage therethrough for connecting a pressure fluid conduit to thehammer, said tubulararm having an elbow bend therein at its end remote from. said cylinder and. said means extending through said tubular arm comprising anv elongated rod extending from a location adjacent the corresponding end of. saidpistonto a location adjacent said tubular bend, andball elements disposed in said arm between said tap pin and the adjacent end of said rod.

3. A pneumatic tap hammer comprising a cylinder, meansproviding a transverse partition in saidcylinder intermediate the length thereof, end plugs secured one in each end of said cylinder, a piston slidably mounted in said cylinderbetween said transverse partition and one of said end plugs, a valve plunger in saidcylinderbetween said transverse partition and the otherend plug, saidoneend plug having a bore extendingtheretlirough,'atubular arm having .one endreceived in thebore of said .one plug and extending outwardly from said one plug, means releasably connecting said arm to said one plug, a tap pin movably mounted in said arm at the other end thereof, means extending through said tubular arm from said tap pinto said piston for transmitting movement of said'pistonto saidtap pin, a frame secured at one end to said arm at a location adjacent said cylinder and having its other end disposed adjacent said tap pin and its intermediateportion spaced from theintermediate portion of said arm, said frame including two members pivotally connected together with their. ad-

jacentiend's overlapping'to' provide a leveragefor manually 'forcing'jsaid outerend ofsaid" frame toward said tap pin; said transverse partition.

having a" valve seat on the side thereof "adjacent end plug and said valve plunger resiliently urg-- ing said plunger into valve"closing'engagement with said valve seat, a" valve operating lever means extending versepartition and said piston, said cylinder having'a venttopening connected tosaidspace for venting pressure fluid therefrom, spring means acting between said piston and said'one end'plug end plug in registrywith the fluid passage therethrough for connecting a' pressure fluid conduit to theahammer, said arm being, substantially straight, said frame extending substantially around three-sides of .a rectangle, and an abut- -ment plate carried by said frame at the/end thereof remote .from said cylinder. in opposition to the adjacent end of said arm;

4. A pneumatic tap hammer-comprising a cylinder, means providing a transverse partition insaid cylinder intermediate the lengththereof, end plugs secured one in each end-of said cylinder, a-piston slidably'mounted in said cylinder between said transverse partition and one. of said end plugs, a valve plunger in said-cylinder between said transverse partition and the other end plug, said one" end plug having a bore extending'therethrough, 'a tubular arm having-one end received-in thebore of said one plug'and extending outwardly from said one plug, means releasably'connectingsaid arm to said one plug, a tap pin movablymounted in said arm at the other end thereof,- means extending through said tubular arm from said tap pin to said piston for transmitting movement of said piston to said tap pin, a frame secured at one end tosaid arm at arlocation adjacent said cylinder and having its other end disposed adjacent said-tap pin and its intermediate portion spaced from the intermediate portion of said arm, said frame including two members pivotally connected together with their adjacent endsoverlapping'to provide a leverage for manually forcing said outer end of said frame toward said tap pin, said transverse partition having a valve seat on the side thereof adjacent said valve plunger and a fluid passage leading from said valve seat to the other side thereof, said other end plug having a guide means thereon maintaining said valve plunger in alignment with said valve seat and a fluid passage therethrough, spring means acting between said other end plug and said valve plunger resiliently urging said plunger into valve closing engagement with said valve seat; a'valve operating lever mounted on said cylinder, means extending through said transverse partition con necting said lever to said valve plunger for manually opening said valve to admit fluid to said transverse partition and to the space between said transverse partition and said piston, said cylinder having a vent opening connected to said space for venting pressurefluid therefrom, spring means acting between said piston and said one end plug resiliently urging said piston toward said transverse partition, a fitting secured to said other end plug in registry with the fluid passage therethrough for connecting a pressure fluid conduit to the hammer, an abutment plate carried by said frame at the end of the latter remote from said cylinder; and means providing a universal connection between said frame and said abutment plate.

5. A pneumatic tap hammer comprisinga cylinder, end plugs secured one at each end of said cylinder, one of said end plugs having a bore extending coaxially therethrough, an elongated tubular arm having one end received in the bore of said one'end plug, means detachably connecting said arm to said one end plug, a piston reciprocable in said cylinder adjacent said'one end plug, a tap pin movably mounted in said arm at the other end of the latter, means extending through said arm from said tap pin to said piston for transmitting movements of said piston to said tap pin, a two-part frame secured at one end to said arm adjacentsaid'cylinder and having; its other'end adjacent said tap pin and its intermediate portion spaced from said arm, a pressure plate on said other end of said frame and opposed to said tap pin, the two parts of said frame being pivotally interconnected intermediate the length of the frame and having overlapping end portions providing leverage for manually forcing said pressure plate toward said tap pin, a fitting secured to the other end plug for connecting a pressure fluid conduit thereto, said other end plug having a fluid passage extending from said fitting to the interior of said cylinder adjacent said other end plug, valve means in said cylinder between said other end plug and said piston for controlling the application of fluid under pressure to said piston, said cylinder being provided with a vent for releasing fluid under pressure therefrom, and manually actuated lever means mounted on said cylinder and connected to said valve means for operating the latter. 1

GEORGE C. CURRENT.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

